Governor.



Patented Apr. i6, I90I.

F. L. wmmoma.

G 0 V E B N 0 R.

(Applieation led Mar. 13, 1900.)l

(No Model.)

7 .Il Il Willi/I1.

/A/VEIVTOR.

fr, I

1H: onlus PETERS :204l Puofauwa., WASHINnTON. u4 c.

Y NiTED STATES FRANK LEONARD WHITMORE, OF BELVEDERE, ENGLAND, ASSIGNORTO FRASER t OHALMERS, LIMITED, OF LONDON, ENGLAND.

GOVERNOR.

SPECIFICATION forming part of Letters Patent No. 672,142, dated April16, 19051.

Application filed March 13,1900. Serial No. l8,530. (No model.)

T0 all whom, it 1v1/ay concern:

Be it known that I, FRANK LEONARD WHIT- MORE, a subject of the Queen ofGreat Britain, residing at Belvedere, in the county of Kent, England,have invented a certain new and useful Improvement in Governors forRegulating the Speed of Gas or Air Compressors or Pumps, of which thefollowing is a specification.

The invention relates to an improvement in governors for regulating thespeed of gas or air compressors or machines for pumping Water orotherliquids, the object of same being to provide an apparatus which willregulate with certainty the speed of the compressing-engine by thevarying pressure of the compressed gas or air, or in the case ofpumpingengines by the varying head of liquid to-be pumped. The apparatusis adapted to act directly upon the steam-supply in the case of asteam-engine or to regulate the watersupply in a water-motor, such as isfrequently used to drive a compressor or pump or to regulate the switchof an electric motor for the same purpose.

The invention is illustrated in the accompanying drawings, in which-Figure 1 is a sectional elevation of the apparatus. Fig. 2 is a sectionat right angles on line w w, Fig. 1. Fig. 3 is a sectional plan on lineFig. 2. Fig. 4 is a sectional plan on line y y, Fig. 2. Fig. 5 is asectional elevation on line z a, Fig. 4; and Fig. 6 is a view of one ofthe iiy-ball arms of the governor detached.

The apparatus consists of two main portions-a speed-governor A of theily-ball type and a gas or air pressure governor B. This latter consistsof a cylinder 1, having a plunger 2 connected by a pivotally-hung link 3to a spring 4, secured in the cylinder. The upper part of the plunger isconnected by a link 5 to a lever 6, pivoted at 7 and carrying at itsfree end an adjustable link 8, connected to one end of a floating lever9, pivotally hung at 10 to an adjustable weighted lever 1l, the free end12 of lever 9 being adapted to be attached direct or by suitableconnections to the cut-off or switch mechanism of the engine or motordriving the compressor or pump, so that any movement of this end of thefloating lever 9 will regulate the speed of the engine or motor. Thelever 1l is pivoted to a bracket 13 on the `governor A and is connectedat 14 to a collar 15 on a spring-box 16, surrounding a spindle 17,supported in the casing 18 of the governor A, and which spindle isdriven by a gear 19 or in some suitable Way from the engine or motor. Inthe box 16, or it may be a part serving the same function, and thereforeequivalent thereto, is a spring 20, surrounding the spindle 17, which atthis point has a shoulder 2l, on which is supported a sleeve 22, on theoutside of which is carried a spring 23, resting on a collar 24 of thesleeve, which collar moves and is guided in the box 16. The spring isfurther retained in position by a head 25, secured to shaft 17, saidhead carrying bracket-arms 26, on which are pivotally mounted theweighted arms 27, forming the fly-balls of the governor. The arms arebell-cranked in shape and are connected to links 28, pivotally connectedin turn to lugs 29, cast on the boX 16. The use of this link between theball-arm and the springbox is an important feature, as the effect is toincrease the effective leverage of the governorballs the further theyfly out. rlhe effect of this link on the leverage of the ball can beseen by comparing the distances marked c in Fig. l, and d in Fig. 6,which show the ball at the eXtreme inner and outer positions,respectively. The same result may be obtained by the use of a roller onthe governor-ball arm working-on an inclined or curved plane on thespring-box, which in this case is the equivalentof the link.

Returning to the pressure-governor B, the 'cylinder 1, it will be seenin Figs. 4 and 5, communicates with a cylinder 30 by a passage 31, whichmay be closed or fully apertured by a screw 32. Such cylinder 30contains aplunger 33, carrying a weight- 34,which plunger is connectedby a pivotally-h ung arm 36 and link 35, which is pivoted at 37 with thearm 3 of plunger 2, so that the spring 4 may also operate on plunger 33.The action of the spring 4 may be regulated by adjusting the tension onthe spring by means of the screwed rod 38.

The two cylinders 1 and 30 are kept full of oil from a supply-tank, thesurface of the oil IOO in which is acted on by the air or gas pressure,39 being the pipe through which the oil is forced.

The weight 34 moving in its cylinder acts as a cataract-piston, the fiowof oil from one piston to the other being regulated by the screw 32, sothat the speed movement of the plunger 2 can be controlled. The weightmay be arranged, as shown, so that its leverage helps the spring bybalancing a portion of the load due to the gas or air pressure acting onthe plunger, or it may be arranged so as to increase the load on thespring.

Instead of the arrangement shown the pivot-point 37 might be formed as aspindle operated by a short arm from arm 3, such spindle passing througha gland in the side of cylinder 1 to the cataract-cylinder 30, which,with its weight, might be separated from cylinder 30.

It will be seen that the fioating lever 9 has two centers 10 and 40, onwhich it can move. When the point 40 acts as the fulcrum, the movementofthe level' is controlled by the gas or air pressure only. For example:Suppose that the gear that drives the speed-governor were to fail,thelever 11 would fall to its lowest position and remain there. The point10 would then act as the fulcrum, and the gas or air pressure rising,due to the increased speed of the engine, would force the plunger 2 up,and with it the innerend of the fioating lever 9, thus reducing thesupply of steam and preventing the engine from running too fast; or,again, suppose any of the gas or air mains or receiver were to fail,causing the gas or air pressure to drop, the plunger 2 would then droptoits lowest point, the point 40 would act as the fulcrum, and the speedof the engine would be controlled entirely by the speed-governor.

Turning to the speed-governor it will be seen that the centrifugal forceof the revolving balls is made to lift the box 16 and sleeve 22 againsta load made by compressing one or both of the springs 20 and 23, thespring 2O being compressed against the under side of collar 24 and thespring 23 against the head 25. The collar 24 is held down by the spring23 on to the shoulder21 of the spindle 17. The spring-box 16 is madewith an internal shoulder 42, so that in the lift of the governor thisshoulder comes in contact with the under face of collar 24 and preventsspring 2O being compressed any further, so that after this takes placethe remainder of the governor lift is accomplished against the action ofthe upper spring 23. This latter spring is adjusted, so that the initialforce exerted by it is equal to or slightly greater than the forceexerted by the lower spring when the shoulder 42 comes in contact withthe collar 24.

The free length of the lower spring is made less than the distance apartof the two faces between which it is compressed when the governor is inits lowest position, so that until the governor has lifted the amount ofthis difference the lower spring does not begin to be compressed and thecentrifugal force of the governor-balls has simply to overcome thedead-weight of the spring-box and spring and also that due to thecounterweight and unbalanced weight of lever 11. This amount ofdead-weight can be adjusted so that at a very low speed of the governorthe centrifugal force of the balls will be sufficient to balance it andkeep the top of the lower spring just up against the collar 24, whichspeed necessary to do this we may call the minimum working speed of thegovernor. This last point is one of great importance, as it prevents thenuisance of the engine continually stopping when only a small quantityof gas or air is required to be used. For example: Take the case of anair-compressor for driving rock-drills in which the air is compressedinto a receiver from which the rock-drills draw their supply. Supposethe compressor to be running at its maximum speed-say seventy-fiverevolutions per minute -with the air in the receiver at its normalworking pressure-say eighty pounds per square inch. Now suppose all therock-drills are shut off. The air-pressu re in the receiver will rise,force out the plunger 2, and the compressor will run at agradually-diminishing speed until it reaches its minimum working speed,as above. The small quantity of air now being compressed will escapethrough the usual reliefvalves on the air-receiver, which are set toblow o a few pounds above the working pressure, and the compressor willbe prevented from stopping, owing to the fact that directly it slowsdown below its minimum working speed the speed-governorwilldrop quicklyto its lowest position, thus considerably increasing the supply of steamto the compressor.

The advantage gained by having the arrangement of two separate springs,as described above, can also be probably best understood from an actualexample. Take the case of an air-compressor working as describedaboVe-'L`. c., its maximum working speed seventy-five revolutions perminute. The speed-governor will then be set, so that at this speed theinternal shoulder 42 on the spring-box 16 will be just touching thecollar 24, so that for any speed less than seventyfive revolutions theballs will be acting against the lower spring only. Now suppose theairmain burst, the compressor would want to race away; but by the timethe speed had increased to about eighty-two revolutions the governorwould have risen to its highest position against the resistance of theupper spring 23, thus shutting off the supply of steam and maintaining asafe speed. In the governor fitted with one spring only the speed of theengine would have to increase to about one hundred revolutions beforethe governor could have risen to its highest point and shut off thesupply of steam. It might be supposed that a result could be obtained bythe IOO IIO

use of one long spring, which would be practically as good as thatobtained by the combination of two springs, as described above. This,however, is not so, as two points are essential for correct governing:first, the spring must be at its free length when the governor is at ornear to its lowest position; second, a large spring-load is requiredwhen the governor is at its highest position, so as to obtain agreatrange of spring load throughout the working lift of the governor.

The principal feature in the action oi' this airgovernor is the resultobtained by the speed and pressure governors working in combination witheach other, their combined actions overcoming the diliculty of governorhunting that has been existent in governors of other design up to t-hepresent.

A compressor varies in speed according to the amount of air required orrock-drills in use and may therefore be at any time from zero to themaximum capacity. When steam is employed, the mean steam-pressure ispractically constant, whether running at twenty or seventy revolutions.The only difference in the steam-pressure would be due to the highervelocity of steam and air through the ports, which is triiiing. Thepoint of cut-off is, however, not constant, as the boiler-pressure maydrop at any time, and in case of a trip-gear engine the closing of thesteamvalves after they are tripped takes time. This latter being thecase, the point of cutoft must be later vwhen running at a slow speedthan when at a high speed in order to produce the same mean pressure.Suppose a compressor fitted with a governor which has not this featureis running at twenty revolutions and the tripping-point in thesteam-cylinder is at twenty-tive per cent. of the stroke, the actualcut-o point would be almost directly after-say twenty-six per cent. Inother words, there would be a sharp corner in the diagram, owing to thecompressor running slowly. Now supposing six-rock-drills are put on, thepressure will begin to drop in the air-receiver, and consequently theplunger in the air-governor. This produces a later cutoff and highermean pressure. The engine at once increases in speed, and as itincreases in speed the mean pressure is still more increased, owing tothe actual cut-off point being extended, due to the higher speed. Inother words, the sharp corner becomes a curve, starting from where thesharp cornerI was. It will be therefore seen that the mean pressure isdoubly increased, and is consequently more than required, which willdrive the air-pressure higher than is necessary in the receiver or to aheight above the required pressure sufficient to extend the air-governorplunger and produce a cut-oft point that will give less mean pressure.As soon as the mean pressure drops the engine slows down, this time to aspeed slower than is necessary, due to same reason of double decreasingthe mean pressure. Thus the compressor keeps hunting. The fact that thisgovernor has a different position for every speed of the engine entirelyovercomes this difficulty.

In the case of a machine for pumping Water or other liquid thepressuregovernor would be in communication with an airyessel placedclose to the pump-cylinder. As the pressure of air in this vessel wouldvary directly according to the head of water being pumped, the engine ormotor driving the pump would be regulated by the head against which thepuinp was working.

What I claim isl. In combination a gas or air pressure governor, aplunger carried thereby, a iioating lever connected to aspeed-regulating device of a motor and controlled by said plunger, aspeed-regulating governor driven from said motor, and a lever operatedby said speed-governor and carrying said floating lever so that thespeed-regulating device of the motor may be controlled either by thespeedgovernor or the gas or air governor or by the two working togethersubstantially as described.

2. The combination with the arms of a governing device of a part carriedby same, a spring supported by said part and a part against which thespring may be compressed, the free length of such spring beingless thanthe distance apart of the two parts so that until the governor haslifted the amount of this difference against the Weight of the parts thespring does not begin to be compressed substantially as described.

3. The combination with a gas or air pressure governor of aspeed-governor, a box carried by the latter a spring in said box,asleeve means for supporting saine, a spring carried by said sleevecompressible only after the first has been compressed, ball-armscontrolling the lift of the box, a lever connected to the box andadapted to operate the speedregulating device of a motor and means forcontrolling said lever from the gas or air pressure governorsubstantially as described.

4.' The combination in a gas or air pressure governor of a cylinder forcontaining oil or liquid, a weight adapted to work in same, a furthercylinder a plunger in the latter, a connection between the plunger andthis weight said plunger being moved by the gas or air pressure so thatthe Weight acts as a cataractpiston controlling the speed of movement ofthe plunger substantially as and for the purpose described.

5. The combination with a plunger of a gas or air compressor governor ofa floating lever one end of which is operated on by said plunger whilethe other end controls the speedregulating device of a motor, a pivotedlever, one end of which carries said lioating lever, a spring-box of aspeed-governor to which the other end of the pivoted lever is connectedand governor-arms by which the movement of the spring-box is controlled,the arrangement enabling a slight increase in the IOO TIO

: eri/2,142

1o by the gas or air pressure governor and the other controlling thespeed-regulating device of the motor substantially as and for'thepurpose described.

In testimony whereof I have hereunto set my hand in the presence of twosubscribing 15 witnesses.

FRANK LEONARD WHITMORE.

Witnesses:

WALTER J. SKERTEN, JOSEPH LAKE.

